Little is known about the emergence, extent and the impact of sleep disturbances on disease- related symptoms, or on family functioning and health outcomes in newly diagnosed children and their parents. The purpose of this project is to gain a better understanding about sleep and the impact of sleep disturbances in 2-5 year-old children recently diagnosed with JRA and their parents, and in aged-matched typically developing children and their parents, and examine how child and parental sleep interrelate. Information from this study is important as it may provide a better understanding about some ofthe mechanisms that may underlie sleep disturbances and disease-related symptoms, as well as provide information to design interventions to improve sleep in parents of children with chronic illness and their child. Therefore the primary aim of this study is to determine the feasibility and acceptability of laboratory-based polysomnography (PSG) and home-based actigraphy in 2-5 year-old children recently diagnosed with JRA and in age-matched typically developing control children. Secondary aims of this study are to 1) examine sleep disturbances in 2- 5 year-olds with JRA to typically developing aged-matched control children and to 2) examine the synchrony between parent and child sleep in 2-5 year-olds recently diagnosed with JRA to aged-matched typically developing control children.